Mike's Notes

I found this great article about the world's time zones. This will needed to be added to Pipi in the future.

The code example below is for New York

Resources

• https://en.wikipedia.org/wiki/Tz_database
• https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
• https://www.iana.org/
• https://www.iana.org/time-zones

tz database

Wikipedia:

The tz database is a collaborative compilation of information about the world's time zones and rules for observing daylight saving time, primarily intended for use with computer programs and operating systems. Paul Eggert has been its editor and maintainer since 2005, with the organizational backing of ICANN. The tz database is also known as tzdata, the zoneinfo database or the IANA time zone database (after the Internet Assigned Numbers Authority), and occasionally as the Olson database, referring to the founding contributor, Arthur David Olson.

Its uniform naming convention for entries in the database, such as America/New_York and Europe/Paris, was designed by Paul Eggert. The database attempts to record historical time zones and all civil changes since 1970, the Unix time epoch. It also records leap seconds.

The database, as well as some reference source code, is in the public domain. New editions of the database and code are published as changes warrant, usually several times per year.

...

Move to ICANN

ICANN took responsibility for the maintenance of the database on 14 October 2011. The full database and a description of plans for its maintenance are available online from IANA.

Code example

# Rule  NAME    FROM    TO      TYPE    IN      ON      AT      SAVE    LETTER/S

Rule    US      1918    1919    -       Mar     lastSun 2:00    1:00    D

Rule    US      1918    1919    -       Oct     lastSun 2:00    0       S

Rule    US      1942    only    -       Feb     9       2:00    1:00    W # War

Rule    US      1945    only    -       Aug     14      23:00u  1:00    P # Peace

Rule    US      1945    only    -       Sep     30      2:00    0       S

Rule    US      1967    2006    -       Oct     lastSun 2:00    0       S

Rule    US      1967    1973    -       Apr     lastSun 2:00    1:00    D

Rule    US      1974    only    -       Jan     6       2:00    1:00    D

Rule    US      1975    only    -       Feb     23      2:00    1:00    D

Rule    US      1976    1986    -       Apr     lastSun 2:00    1:00    D

Rule    US      1987    2006    -       Apr     Sun>=1  2:00    1:00    D

Rule    US      2007    max     -       Mar     Sun>=8  2:00    1:00    D

Rule    US      2007    max     -       Nov     Sun>=1  2:00    0       S

....

# Rule  NAME    FROM    TO      TYPE    IN      ON      AT      SAVE    LETTER

Rule    NYC     1920    only    -       Mar     lastSun 2:00    1:00    D

Rule    NYC     1920    only    -       Oct     lastSun 2:00    0       S

Rule    NYC     1921    1966    -       Apr     lastSun 2:00    1:00    D

Rule    NYC     1921    1954    -       Sep     lastSun 2:00    0       S

Rule    NYC     1955    1966    -       Oct     lastSun 2:00    0       S

# Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]

Zone America/New_York   -4:56:02 -      LMT     1883 November 18, 12:03:58

                        -5:00   US      E%sT    1920

                        -5:00   NYC     E%sT    1942

                        -5:00   US      E%sT    1946

                        -5:00   NYC     E%sT    1967

                        -5:00   US      E%sT